1. Field of the Invention
The present invention relates generally to image processing apparatuses. More particularly, the present invention relates to an image processing apparatus and an image capturing apparatus for determining whether an image includes a detection target, an image processing method for these apparatuses, and a program for allowing a computer to execute the method.
2. Description of the Related Art
For image capturing apparatuses, such as digital still cameras and video cameras, methods for detecting an area including a specific subject from a captured result and performing control operations, such as auto focus and auto exposure control operations, on the basis of the captured result of this area have been suggested. Such methods for detecting an area including a specific subject mainly employ a human face as the specific subject. The methods include a method for allowing a discriminator to previously learn face patterns utilizing pattern recognition methods, such as, for example, the eigenface, the neural network, and the support vector machine, to form the discriminator, and a method for determining a local maximum value of correlation values on the basis of a result of matching of a target and an average face template and extracting a face candidate on the basis of this local maximum value.
Regarding such methods, for example, a method for automatically setting an image capturing mode according to the number of and the size of areas including, for example, a face (see, for example, Japanese Unexamined Patent Application Publication No. 2001-330882 (FIG. 1)) has been suggested. A method for estimating a distance to a subject having a target face on the basis of the size of an area including the face and controlling a focusing operation has also suggested (see, for example, Japanese Unexamined Patent Application Publication No. 2003-75717 (FIG. 1)). In addition, a method regarding detection of an area including a face in a template matching operation using templates has been suggested (see, for example, Japanese Unexamined Patent Application Publication No. 2004-30629 (FIG. 1)). Furthermore, a discriminator including a plurality of weak discriminators generated by group learning according to a boosting algorithm and an adder for adding values output from the weak discriminators to perform the weighted majority decision has been suggested (see, for example, Japanese Unexamined Patent Application Publication No. 2005-157679 (FIG. 1)).